Hi Jason,
I have run into this as well when I wanted to create a menu in a
DockedCell that displayed the current set of files in a particular
directory. One issue is that one has to trigger any Dynamic that is
in the cell, and for some cases one doesn't want something constantly
testing the cou=mputer's filesystem for changes. I had played with
Refresh and things like that.
A solution that I came up with, that served my particular application
needs was to create a reason for a menu to update.
So, my menu was generated through a function likethe following. Note
that it has an argument, but the parameter in the arrument is not used
in the funtion:
myMenu[z_] :=
ActionMenu["Open...",
FileNameTake[#, -1] :> SystemOpen[#] & /@
FileNames[{"*"}, {$UserDocumentsDirectory}]]
Note that if you create a cell with this menu in it it will not update
if you add or remove a file in $UserDocumentsDirector:
TextCell[Dynamic[myMenu[1]], "Text"] // CellPrint
The trick now is to introduce a new function which has as its only
purpose to change the value of a parameter: $MysteryParameter. Make
sure that that parameter is Unprotected if it is in a Package.
$MysteryParameter will be used in the argument to myMenu to force it
to trigger the Dynamic. And this will be acomplished by having the
Cell that contains the menu have a CellEventAction.
$MysteryParameter = 1;
Toggle$MysteryParameter[] :=
Switch[$MysteryParameter,
1,
$MysteryParameter = 2,
2,
$MysteryParameter = 1,
_,
$MysteryParameter = 1];
And finally one intruduces a CellEventAction to the cell that causes
the value of $MysteryParameter to change and thereby causes the myMenu
in the Dynamic to update because its argument has changed.
TextCell[Dynamic[myMenu[$MysteryParameter]], "Text",
CellEventActions -> {"MouseMoved" :> (Toggle$MysteryParameter
[])}] // \
CellPrint
Or, in a DockedCell
SetOptions[EvaluationNotebook[],
DockedCells -> {
MakeBoxes@
TextCell[Dynamic[myMenu[$MysteryParameter]], "DockedCell",
CellEventActions -> {"MouseMoved" :> (Toggle$MysteryParameter
[])},
StripOnInput -> True]}
]
I hope this helps....
--David
http://scientificarts.com/worklife
On Oct 20, 4:51 am, Jason Ledbetter <jasonbr... at gmail.com> wrote:
> Folk,
> I'm attempting to create a dynamically-appearing set of choices/menus usi=
ng
> ButtonBar in a notebook window but I've been unable to get the desired
> affect to date. I've cobbled together the following code which almost doe=
s
> what I'm looking for but I could use some pointers in getting the rest of
> the way.
>
> The goal here is for the "topMenu" items to appear when the notebook is
> first instantiated and for the "secondMenu" option to appear when a
> "topMenu" option is selected. As it stands now, I'm having to start with =
the
> "secondMenu" option pre-defined to a bogus value.
>
> If I were to abstract my goal some more, I'm trying to figure out how to
> dynamically add/remove RowBox items that include ButtonBars from the
> notebook based on options that are selected.
>
> I'm guessing that I somehow need to programmatically generate the content=
s
> of a Dynamically wrapped RowBox (e.g., Dynamic[RowBox[...]]) but I'm not
> quite sure how to go about that just yet.
>
> Any help is greatly appreciated...
>
> Here's what I have thus far:
>
> --snip--
> Module[
>
> {topMenu, secondMenu},
>
> topMenu = {"option1", "option2"};
> secondMenu = {"No option selected"};
>
> menuChoice[choice_] := Module[{},
> Switch[choice,
> "option1", secondMenu = {"one", "selected"},
> "option2", secondMenu = {"two", "selected"}, _, Print[choice=
]
> ]];
>
> CreateWindow[DockedCells -> Cell[
> RowBox[
> {
> ToBoxes[
> ButtonBar[ToString[#] :> menuChoice[#] & /@ topMenu]
> ],
> ToBoxes[
> Dynamic[
> ButtonBar[ToString[#] :> menuChoice[#] & /@ secondMenu=
]
> ]
> ]
> }
> ],
> "DockedCell"],
> TextAlignment -> Center
> ]
> ];
>
> --snip--
>
> thanks,
>
> -jbl